Improved bolt-fastenings for boiler-heads



UNITED STATES PATENT OFFICEO EDWARDGLARK, oE NEW YORK, N. Y.

IMPRQVED BOLT-FASTENINGS FoaBolLER-HEADS.'

Specific-ation forming part of Letters Patent No. 54, |13, dated April 24, 1866.

To all whom it may co'acem:

Beit known that I, EDWARD CLARK, of the city and county of New York, State of New York, have invented a new and Improved Bolt-Fastening for Boiler-Plates; and Ido hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying` drawings, making a part of this specification, in Which- Figure l shows the thimble, the bolt, the` nut, and two plates to be secured together thereby, which bolt may be tubular or solid.

Fig. 2 shows the bolt-fastening applied to two plates ready to be drawn together. Fig. 3 is a similar view, showing the bolt drawn tight.

Fig. 4 is a perspective View ot the thimble.

Similar letters of reference indicate corresponding parts in the several figures.

' The object of this invention is to obtain a bolt-fastening for boiler-plates and otherA purstand my invention, l will describe its construction and operation. l y

Bolt fastenings hitherto used by boilerworkers are constructed With square heads, so that it is frequently necessary' to make handholes through the plates ot' the boiler in order to insert the bolts, the heads being on the inside ot the plates. To obviate this difficulty I construct the heads ofniy bolts ot' a conical forni, as shown in the drawings, the cone being larger at its base than the stem of the bolt,

and slightly less in diameter than the hole through the plates to receive it. This cylindro-conical bolt A has a male screw cut on its stem to receive a nut, B, and it is passed head first through the holes which are made through thef'plates C C to receive it.

In conjunction with such bolt I employ a splitl tube or thimble D, the .external diameter of which is nearly equal to the bolt-holes through the boiler-plates, and the internal diameter of this tube Dis slightly greater than the diameter ofthe stem of the bolt. One end of this.tube may be made thinner than the opposite end, if desirable.

The manner of using this fastening is as follows The tube D is slipped upon the stem of the bolt A, andboth are passed through the plates G C', as shown in Fig. 2. The nut B is screwed upon the outer end of the screwstem A and set up against the outer plate. Then, by further screwing up the nut B the bolt is drawn in a direction with its length, and the circular head or cone a is caused to spread out the inner end of the thimble D, thus preventing the bolt from being drawn through the hole. As the conical head of the bolt expands the inner end of the tube or thimble D and increases its diameter it is obvious that the bolt-head cannot be drawn through the plates, consequently the fastening Will be very secure and perfectly tight. D should be longer than the thickness ot' the two plates'or objects through which they are passed to allow the inner ends ot' the tubes to be expanded by the conical heads of the bolts as these bolts are setup. If desirable, Washers may be interposed between the nuts and the outer ends ofthe tubes D.

Hav-ing thus described myinventon', what I claim as new, and desire to secure by Letters Patent, is-

l. The method of securing together boiler and other plates by the employment of conicalhead bolts, in combination with tubes or thim bles, substantially as described.

2. The conical-head screw-bolt A, in combinationwith split tube D, substantially as described.

EDWARD CLARK.

Vitnesses FRED. J. BOLAND, AUGUSTUS LELAND.

The thimbles 

